Information about these experiments was uncovered by Professor Susan Mokotoff Reverby of Wellesley College. Reverby found the documents in 2005 while researching the Tuskegee syphilis study, in Cutler's archived papers, and shared her findings with United States government officials.[1][4]

While the Tuskegee experiment followed the natural progression of syphilis in those already infected, in Guatemala doctors deliberately infected healthy people with the diseases, some of which can be fatal if untreated. The goal of the study seems to have been to determine the effect of penicillin in the prevention and treatment of venereal diseases. The researchers paid prostitutes infected with syphilis to have sex with prisoners and some subjects were infected by directly inoculating them with the bacterium.[1] When the subjects contracted the disease they were given antibiotics. Although adequate penicillin therapy was prescribed for 76% of subjects, completion of therapy was documented for only 26%.[citation needed]Francis Collins, the NIH director at the time of the revelations, called the experiments "a dark chapter in history of medicine" and commented that modern rules prohibit conducting human subject research without informed consent.[6]

The study appears to have ended in 1948, partly because of medical “gossip” about the work, and partly because penicillin was very costly. However, some follow-up laboratory testing and patient observation continued until the early 1950s.

Additionally, similar research was also conducted on the transmission and prophylaxis of gonorrhea and chancroid.[7] The subjects for all of the STD experiments consisted of female sex workers, prisoners, soldiers, and mental hospital patients; the Centers for Disease Control and Prevention acknowledges that "the design and conduct of the studies was unethical in many respects, including deliberate exposure of subjects to known serious health threats, lack of knowledge of and consent for experimental procedures by study subjects, and the use of highly vulnerable populations."[7]

In October 2010, the U.S. government formally apologized and announced that the violation of human rights in that medical research was still to be condemned, regardless of how much time had passed.[8][9][10]In a joint statement, Hillary Clinton and Kathleen Sebelius said:

Although these events occurred more than 64 years ago, we are outraged that such reprehensible research could have occurred under the guise of public health. We deeply regret that it happened, and we apologize to all the individuals who were affected by such abhorrent research practices. The conduct exhibited during the study does not represent the values of the US, or our commitment to human dignity and great respect for the people of Guatemala.[11]

"It is clear from the language of the report that the U.S. researchers understood the profoundly unethical nature of the study. In fact the Guatemalan syphilis study was being carried out just as the “Doctors’ Trial” was unfolding at Nuremberg (December 1946 – August 1947), when 23 German physicians stood trial for participating in Nazi programs to euthanize or medically experiment on concentration camp prisoners."[13]

The U.S. government asked the Institute of Medicine to conduct a review of these experiments.[1] Separately, the Presidential Commission for the Study of Bioethical Issues was asked to convene a panel of international experts to review the current state of medical research on humans around the world and ensure that such incidents cannot be repeated.[1] The Commission report, Ethically Impossible: STD Research in Guatemala from 1946 to 1948, published in September 2011, concluded that "the Guatemala experiments involved unconscionable basic violations of ethics, even as judged against the researchers' own recognition of the requirements of the medical ethics of the day."[14][15]

Human rights activists have called for subjects' families to be compensated.[3]